Coherent and incoherent tunneling currents in an exciton-polariton Josephson Junction

An exciton-polariton (EP) condensate can be considered as the charge-neutral analog of a superconducting BCS state, and manifests similar macroscopic quantum behavior, such as the Josephson effect. A boson Josephson junction, inspired by the double-well trap in cold atom condensates, can show the distinct properties of a dilute quantum gas.

Existing EP junction experiments focus on optical trapping and control of polaritons in a non-equilibrium limit, which makes it difficult to use EP junctions in quantum coherent technology. However, recent experiments show that the polariton condensate and the non-condensate polariton residues can be prepared in a quasi-equilibrium state satisfying Bose-Einstein statistics, which enables their use in a wide range of applications in the equilibrium limit. This enables EP devices analogous to superconducting junctions.

We develop a theory for the electrical control of an EP junction trapped by the potential arising from its exciton component. We explore the coherent dynamics of the upper and lower EP condensates, such as switching between different oscillations and chaotic trajectories. We also explore the time evolution of coherent and incoherent (thermal) EP populations due to tunneling, examine the stability of each dynamical mode, and draw a comparison to the superconducting RCSJ model.